CDRF Invests in Research to Show How Milk Keeps Bones Strong

Van Loan Photo

Physiologist Marta Van Loan (right) and chemist Erik Gertz examine a tray of serum samples to be analyzed for markers of bone formation and resorption.

“Milk Does a Body Good”

The slogan, “Milk does a body good,” isn’t just a marketing creation. Scientific evidence demonstrates several health benefits from consuming dairy products. Furthering this understanding of dairy’s health benefits, as well as promoting awareness of its nutritional value, are prominent goals of the California Dairy Research Foundation (CDRF).

Dr. Marta Van Loan, a whole-body physiologist, has partnered with CDRF on a number of projects exploring just how much good milk can really do for a body, as well as the mechanisms behind the benefits. “At CDRF, we really believe in examining the bigger picture,” said Dr. Gonca Pasin, Executive Director at CDRF. “If you want to understand bone health but you’re only looking at calcium and fractures, you’re going to miss important things. By working with scientists with more holistic views, like Dr. Van Loan, CDRF can help expand our understanding of the role dairy plays in these complex areas.”

Human clinical studies are complicated, time-consuming and—most of all—expensive. Animal studies can help us in many preliminary experiments, but at some point questions remain that can only be answered by studying them in the proper context. In order to do human clinical studies, researchers have to recruit and support enough volunteers to make the study representative of the greater population, as well as navigate the much more rigorous restrictions on human studies. “That’s why multiple organizations have to partner together to make these important studies happen,” Dr. Van Loan explained. Research organizations like CDRF are vital in their ability to support effective human studies, which produce the most accurate understandings of human nutrition and health. CDRF has partnered with her on a number of projects to help understand the full impact of dairy consumption on people’s health.

Her latest project, funded in part by California producers’ checkoff dollars from the CDRF, explored the benefits of dairy consumption on reducing bone loss in post-menopausal women. Her group found that eating four extra servings of dairy significantly reduced the amount of bone loss, even when compared to taking a calcium-vitamin D combined supplement. This is a very important finding for post-menopausal women, who make up 80% of Americans with osteoporosis and have a 50% chance of breaking a bone due to osteoporosis.

The Strong Bone Project

Dr. Van Loan’s research provided important new information about bone loss in these women. Bones are constantly changing, she explained, breaking down and reforming themselves. The problem in post-menopausal women is that bone loss often outpaces the reformation of bone. Her group wanted to understand the impact of calcium-vitamin D supplementation, dairy consumption, and no intervention on both bone loss and bone formation.

The findings showed a deeper insight into the workings of the bone and dairy story. Both the calcium-vitamin D supplement and extra dairy servings reduced calcium loss from bones as compared to no treatment at all. And interestingly, there was no significant difference between the supplement and the additional dairy servings—both reduced calcium loss from bones equally well. However, the big difference arose in bone formation. While consuming the extra milk and yogurt, women showed significantly more bone formation than those simply taking the calcium-vitamin D supplement. This means that drinking milk and eating yogurt reduced overall loss of bone. If two women lose the same amount of calcium from their bones, but one adds back in more than the other, she will have denser, stronger bones than the woman who doesn’t build as much bone. Adequate calcium and vitamin D intake on its own can reduce rate of bone loss. But to increase bone building, then dairy does better job.

Calcium Supplements or Milk: What’s Best For Your Bones and Health?

Dr. Van Loan has a hypothesis as to why this difference between calcium supplements and dairy products exists. “For a long time, it was always just ‘calcium, calcium, calcium,’” she said of our mindset toward keeping bones strong. “But it’s not. There’s so much more going on.” Just as bones aren’t made of only calcium, milk isn’t either. Bones are made of a supporting matrix of protein, which provides a framework for the calcium to build on. And milk is a good source of quality protein—something that a calcium supplement doesn’t supply. There’s also magnesium in bones, and magnesium in milk. “Dairy is a high-quality product,” she said, and that’s why you get a higher-quality outcome with it than from a one-dimensional supplement.

Dr. Van Loan acknowledged that dairy takes a beating because of its fat content. “But not even all saturated fats are created equal,” she explains. “They are chemically different, so why would they all produce the same results in people?”. She hopes future work, like the kind she worked on with CDRF, will help show that the saturated fats in milk don’t produce the kinds of poor health effects seen from chemically processed fats like those in processed foods.

She and Dr. Pasin came together five years ago at a dairy conference. “We immediately clicked over the idea of looking at the whole picture of dairy’s role in good nutrition and human health,” Dr. Van Loan said. “The sad truth is that there are still flawed beliefs and biased information floating around damaging milk’s image,” said Dr. Pasin. CDRF will continue to build a credible science-based evidence library on sustaining and expanding the health benefits of milk and dairy products. As Dr. Pasin said, “Yes, milk and dairy products are really needed to optimize bone health and indeed are good for your bones.”